Method for treating von willebrand&#39;s disease

ABSTRACT

Use of factor XIII for treating von Willebrand&#39;s disease. A patient having von Willebrand&#39;s disease is treated by administering factor XIII generally in conjunction with factor VIII concentrate, 1-desamino-8-D-arginine vasopressin (DDAVP) or desmopressin.

BACKGROUND OF THE INVENTION

[0001] Von Willebrand's disease (vWD) is the most common inheritedbleeding disorder and may occur in as many as 1 in 800 individuals. Thevon Willebrand factor (vWF) is heterogeneous multimeric plasmaglycoprotein with two major functions. It facilitates platelet adhesionunder conditions of high shear stress by linking platelet membranereceptors to vascular subendothelium. It also serves as the plasmacarrier for factor VIII. The normal plasma level of vWF is 10 mg/L. ThevWF activity is distributed among a series of plasma multimers withestimated molecular weights ranging from 400,000 to over 20 million. Asingle large vWF precursor subunit is synthesized in endothelial cellsand megakaryocytes, where it is cleaved and assembled into thedisulfide-linked multimers present in plasma, platelets, endothelialcells, and in the basement membrane of blood vessels. All of these poolsof vWF contribute to the protein's main function, which is to promoteattachment of platelets to areas of vessel injury. To optimize theavailability of vWF at the site of injury, a highly active form of theprotein is stored in secretory granules of platelets and of endothelialcells. When these cells sense tissue injury (e.g. by contact withthrombin) they instantly mobilize the stored vWF. The released vWF bindsto glycoprotein Ib (GPIb) on the platelet surface and to components ofthe basement membrane, forming a bridge that can withstand high sheerstress of blood flow. VWF is necessary for this initial attachment ofplatelets to the injured area. Together with other adhesive proteins,such as fibrinogen, fibronectin, and thrombospondin, vWF interacts withthe GPIIb/IIIa on activated platelets and contributes to plateletspreading and aggregation.

[0002] A modest reduction in plasma vWF concentration, or a selectiveloss in the high-molecular weight multimers, decreases platelet adhesionand causes clinical bleeding. Although vWD is heterogeneous, there arecertain clinical features that are common to all the syndromes. With oneexception (type III disease), all forms are inherited as autosomaldominant traits and affected patients are heterozygous with one normaland one abnormal vWF allele. In mild cases, bleeding occurs only aftersurgery or trauma. There are three major types of vWD. Patients withtype I disease, the most common abnormality, have a mild to moderatedecrease in plasma vWF. In the milder cases, although hemostasis isclearly impaired, the vWF level is just below the lower limit of normal,less than 5 mg/L. In type I disease, there is a parallel decrease in vWFantigen, factor VIII activity, and ristocetin cofactor activity, with anormal spectrum of multimers detected by sodium dodecyl sulfate(SDS)-agarose gel electrophoresis. Cultured endothelial cells derivedfrom the umbilical cords of patients with vWD synthesize and secretereduced quantities of vWF multimer and have a two- to fourfold reductionin vWF mRNA.

[0003] The variant forms of vWD (type II disease), which are much lesscommon, are characterized by normal or near-normal levels of adysfunctional vWF. Patients with the type IIa variant of vWD have adeficiency in the high- and medium molecular-weight forms of vWFmultimer detected by SDS-agarose electrophoresis. This is due either toan inability to secrete the high-molecular-weight vWF multimets or toproteolysis of the multimers soon after they leave the endothelial celland enter the circulation. The quantity of vWF antigen and the amount ofassociated factor VIII are usually normal. In the type IIb variant,there is also a loss in high-molecular-weight multimers. However, intype IIb disease, it is due to the inappropriate binding of vWF toplatelets. This forms intravascular platelet aggregates that are rapidlycleared from the circulation, causing mild, cyclic thrombocytopenia.

[0004] Approximately 1 in 1 million individuals have a very severe formof vWD that is phenotypically recessive (type III disease). Type IIIpatients are usually the offspring of two parents with mild type Idisease. However, in many cases, the parents are very mildly affected orare asymptomatic. Type III patients may inherit a different abnormalityfrom each parent (a doubly heterozygous or compound heterozygous state)or be homozygous for a single defect. Type III patients have severemucosal bleeding, no detectable vWF antigen or activity, and may havesufficiently low factor VIII that they have occasional hemarthroses likemild hemophiliacs.

[0005] Prior art treatment of vWD depends on the symptoms and theunderlying type of disease. One type of treatment involves the use ofcryoprecipitate, a plasma fraction enriched in vWF, or factor VIIIconcentrates, which retain high-molecular-weight vWF multimers(HUMATE-P®, KOATE HS®). A second therapeutic option, which avoid the useof plasma is use of 1-desamino-8-D-arginine vasopressin (DDAVP), ordesmopressin.

[0006] However, there are times when treating such patients with theabove-described therapeutic agents produces less than satisfactoryresults, and hemorrhaging continues. Thus, there is a need to developadditional therapies for treating vWD.

DESCRIPTION OF THE INVENTION

[0007] The present invention fills this need by administering factorXIII to patients with vWD, preferably in conjunction with either factorVIII concentrates, plasma cryoprecipitate enriched in vWF, DDAVP ordesmopressin acetate.

[0008] Diagnosis of Von Willebrand's Disease

[0009] Once a bleeding disorder has been determined to be present, thephysician must determine what is the cause of the disorder. Although aprolonged bleeding time is the hallmark of vWD, this laboratory findingis not specific for vWD. Thus, the diagnosis of vWD is definitivelyestablished by means of additional laboratory tests. See Triplett, DA:Laboratory Diagnosis of von Willebrand's Disease, Mayo Clin. Proc.66:832 (1991). These usually include measurements of the amount of vWFprotein present in plasma, the functional activity of the vWF, and theprocoagulant activity of the associated factor VIII.

[0010] Treatment of Von Willebrand's Disease with Factor VIII and FactorXIII

[0011] The method of the present invention improves upon theabove-described treatment of von Willebrand's disease by administeringfactor XIII in conjunction with cryoprecipitate enriched in vWF, factorVIII concentrate, DDAVP or desmopressin acetate. The factor XIII can beadministered at any time alone or at the same time as the othertherapies either to stop a hemorrhage or for prophylaxis.

[0012] Factor XIII, also known as fibrin-stabilizing factor, circulatesin the plasma at a concentration of about 20 mg/ml. The protein existsin plasma as a tetramer comprised of two A subunits and two B subunits.Each subunit has a molecular weight of 83,000 Da, and the completeprotein has a molecular weight of approximately 330,000 Da. Factor XIIIcatalyzes the cross-linkage between the γ-glutamyl and ε-lysyl groups ofdifferent fibrin strands. The catalytic activity of factor XIII residesin the A subunits. The B subunits act as carriers for the A subunits inplasma factor XIII. Recombinant factor XIII can be produced according tothe process described in European Patent No. 0 268 772 B1. The level offactor XIII in the plasma can also be increased by administering afactor XIII concentrate derived from human placenta called FIBROGAMMIN®(Aventis Corp.) or by administration of recombinant factor XIII.

[0013] Administration of factor XIII to a subject is preferablyintravenous. When administering therapeutic proteins by injection, theadministration may be by continuous infusion or by single or multipleboluses. A pharmaceutical composition comprising factor XIII can beformulated according to known methods to prepare pharmaceutically usefulcompositions, whereby the therapeutic proteins are combined in a mixturewith a pharmaceutically acceptable carrier. A composition is said to bea “pharmaceutically acceptable carrier” if its administration can betolerated by a recipient patient. A suitable pharmaceutical compositionof factor XIII will contain 1 mM EDTA, 10 mM Glycine, 2% sucrose inwater. An alternative formulation will be a factor XIII compositioncontaining 20 mM histidine, 3% wt/volume sucrose, 2 mM glycine and 0.01%wt/vol. polysorbate, pH 8. The concentration of factor XIII shouldpreferably be 1-10 mg/ml, more preferably about 5 mg/mL.

[0014] Other suitable carriers are well known to those in the art. See,for example, Gennaro (ed.), Remington's Pharmaceutical Sciences, 19thEdition (Mack Publishing Company 1995).

[0015] Factor XIII can be administered intravenously, intramuscularly orsubcutaneously to treat vWD. The levels of factor XIII in an individualcan be determined by assays well known in the art such as the BERICHROM®F XIII assay (Dade Behring Marburg GmbH, Marburg, Germany). The normaladult has an average of about 45 ml of plasma per kg of body weight.Each liter of blood has 1000 units (U) of factor XIII. A dose of 0.45U/kg would raise the level of factor XIII by about 1% compared tonormal. One unit of factor XIII is about 10 micrograms (mcg) ofrecombinant factor XIII, which contains only the dimerized, ‘A’ subunit.Thus, to raise the level of factor XIII by 1%, one would administerabout 4.5 mcg of the A2 subunit per kilogram weight of the individual.So to raise the level 30% of normal, one would administer 13.5 U/kg. Fora 75 kg individual this would be about 1,012.5 U. Some patients may haveconsumptive coagulopathies that involve factor XIII losses. In suchcases, a higher dosing (e.g., 1-2 U/kg-%) or multiple dosing of factorXIII (e.g., 1-2 U/kg-%-day) may be required.

[0016] Factor VIII concentrate is produced by a number of companiesincluding HEMAFIL M (human, plasma-derived) produced by BaxterHealthcare Corp.; HUMATE-P CONCENTRATE® (human, plasma-derived) producedby Centeon L.L.C.; KOATE-DVI® (human, plasma-derived) produced by BayerBiological; KOATE HP (human, plasma-derived) produced by BayerBiological; MONOCLATEP® (human, plasma-derived) produced by CenteonL.L.C.

[0017] Desmopressin acetate and DDAVP are produced by Rhône-PoulencRorer, Collegeville, Pa., by Ferring Pharmaceutical, Tarrytown, N.Y.,and by Centeon, King of Prussia Pa.

What is claimed is:
 1. A method for treating von Willebrand's diseasecomprising administering to an individual having said disease factorXIII.
 2. The method of claim 1 wherein the factor XIII is administeredto said individual during a bleeding episode.
 3. A method for treatingvon Willebrand's disease comprising administering to an individualhaving said disease factor XIII in conjunction with one or moreadditional therapeutic agents, wherein said therapeutic agent isselected from the group consisting of factor VIII concentrate, plasmacryoprecipitate, desmopressin and 1-desamino-8-D-arginine vasopressin(DDAVP).
 4. The method of claim 3 wherein the factor XIII isadministered prior to the administration of the additional therapeuticagent.
 5. The method of claim 3 wherein the factor XIII is administeredafter the administration of the additional therapeutic agent.
 6. Themethod of claim 3 wherein the factor XIII is administered simultaneouslywith the administration of the additional therapeutic agent.